1. Field of the Invention
The present invention relates to a telecommunication service, and more particularly, to a gateway and routing method for optimizing international roaming call services.
2. Description of the Related Art
With the widespread development of mobile telecommunication technology, users can now enjoy mobile telephone service at any location and are not limited to a fixed location where wire equipment has been deployed. In particular, telecommunication providers offer international roaming call services that allow mobile subscribers to easily communication using their mobile phones. However, the international roaming fee is very expensive because the roaming communication usually goes through two international trunks.
Although there are many low cost approaches in the market, such approaches either require the user to dial several times or require the purchase of additional devices such as SIM cards or external boxes. As a result, such approaches might save money but do so at the expense of lost convenience for the user. Other approaches achieve cost savings by modifying existing mobile communication systems, but the cost of replacing existing communication nodes is relatively high. In brief, a solution is needed to meet the demands of both convenience and routing cost for international roaming call services.